1. Field of the Invention
This invention relates to methods of monitoring and photographing vehicles. In a specific embodiment, the invention is directed to a method of accurately photographing a moving vehicle, preferably a vehicle traveling through a traffic intersection. Preferably, the vehicle is photographed in a predetermined zone within the intersection regardless of the speed of the vehicle, its travel pattern, or the length of the vehicle. Preferably, a selected portion of the vehicle is photographed, such as its license plate or tag.
2. Description of Related Art
Various systems for monitoring traffic in intersections have been proposed, but suffer from one or more shortcomings. Certain devices rely on a predetermined trigger time to take photographs of the vehicle after the vehicle passes over an induction loop in the road. However, in such systems the photograph sometimes "misses" the vehicle if the vehicle is moving either too fast or too slow. Other systems use sensors located at the point where the photograph is taken. U.S. Pat. No. 4,884,072 shows a traffic monitoring device that includes a camera for recording the image of the vehicle in a so-called "danger zone" that corresponds to an induction loop located within the intersection. That device has certain shortcomings, including the need to place the induction loop in the intersection at a point corresponding to the danger zone. Accordingly, the present invention is intended to provide an improved system for monitoring and photographing moving vehicles.